This invention relates, in general, to optical detection devices.
With the diminishing of the historic cold war, new "battle fronts" have become of interest to the defense systems of many countries. For instance, protection of expatriates and diplomats in foreign countries against terrorist activities has become a fore-front interest to more advanced countries. Riot control and control of drug traffickers has also become a major interest to various governments. In these new "battle fields", harm to people and property should be minimized as much as possible.
As an example, in the area of drug trafficking, a U.S. federal agent may desire to temporarily disable an aircraft or helicopter in order to permit a search of the aircraft contents. Complete destruction of the aircraft is unnecessary and counter-productive, and extreme physical harm to individuals within the aircraft is generally undesirable. However, if the engines could be somehow jammed, the aircraft could be grounded long enough for officials to take control of the aircraft.
In the area of terrorism, historical incidents have shown that terrorists use vehicles, manned or unmanned, loaded with explosives, to penetrate protective barriers around diplomatic compounds. If the vehicle could be stopped, such as by jamming the engine of the vehicle, the danger to the facilities and personnel of such compounds could be eliminated. It would be far better to stop the vehicle in its forward progression leaving a safe distance between the vehicle and the compound than to cause an explosion at the barrier.
A device for accomplishing the above objectives would produce a cloud of material in close proximity to the vehicle or aircraft. When an aircraft is to be disabled, a cloud of coagulating substance could be dissipated within close proximity of the aircraft causing the jet/propeller engines to become jammed. The same principle could be used in stopping a moving vehicle. A coagulating material could be dissipated at the front of the vehicle. The material would then be taken into the engine, as the case with aircraft engines, through the air intake and generate a sludge in the engine cylinders. Accordingly, the engine would freeze and the vehicle would stop.
To ensure proper dissipation of the material, engaging mechanism with the carrier device must dissipate the material before the carrier device reaches the aircraft/vehicle. If dissipated too early, the cloud could be avoided altogether by the aircraft/vehicle.
The time at which material is to be dissipated prior to reaching a target is known as stand-off. To achieve the right stand-off, sensors indicating proximity are incorporated.
Experience in sensor technology shows the optical sensors are more accurate and reliable than radar sensors in a high clutter environment. Optical sensors use transmit and receive optical lens to detect targets. A light beam is transmitted, and when reflected back from a target, is received by the receive optical lens telling the sensor a target has been detected. These optical sensors have some associated problems. A distant glint (intense sunlight reflections) may prematurely activate conventional optical sensors. Where such optical sensors have been used in battle, flares have been incorporated as defenses against optical sensors. Furthermore, white phosphorous gas (categorized as an aerosol) is used as a counter-measure to optical sensors. The aerosol reflects the light beam in a similar manner as would a target. The flares or aerosols prematurely detonate the optical sensors neutralizing the effect of the associated device.